Multi-Electroanalytical Method Capable, Duty-Cycled, 0.36 mm² Electrochemical Frontend, Achieving 170dB Current Sensing Range with Extended Compliance Voltage Adopting Feedforward Cancellation

Modern applications require the measurement of diverse analytes, including enzymes, ions, antibodies, and nucleotides [1]. Electrochemical (EC) sensing provides a compact, low-power, and cost-effective solution to meet this need. ECAnalog Front Ends (ECAFEs) with a wide compliance voltage (voltage across counter and working electrodes ∣V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE</inf>-V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WE</inf>∣) and biasing voltage (voltage across reference and working electrodes ∣V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RE</inf>-V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WE</inf>∣) are essential to accommodate the broad redox potential range of diverse analytes. This capability allows the analysis of analytes with unique electrochemical properties, ensuring accurate and stable measurements across different reaction types [1]. Analytes with closely spaced redox potentials, like dopamine and serotonin or lead and copper, require highly precise sensor biasing [2]. This drives the need for high-resolution Digital-to-Analog and Analog-to-Digital Converters (DACs and ADCs) in the ECAFE to ensure accurate detection and separation of such analytes. This work showcases the design of such an ECAFE. While several architectures have been proposed specifically for Chronoamperometry (CA) [3]–[6], CA with Open-Circuit Potentiometry (OCP) [7], or Cyclic Voltammetry (CV) [8]–[10], this work is, to our knowledge, the first to demonstrate a single versatile ECAFE capable of optimally handling all these and more methods. Implementing a single ECAFE for multiple electroanalytical techniques is challenging due to each method's distinct requirements. Chronoamperometry (CA) demands a wide current range (from pA to hundreds of μA), while Open-Circuit Potentiometry (OCP) needs ultra-low leakage currents and a broad voltage range (hundreds of μV to 1-2V). Cyclic Voltammetry (CV) requires precise, configurable voltage profiles to bias the reference electrode. Traditional designs often handle bias generation for CV offchip, adding complexity and susceptibility to noise, and fully analog on-chip generators face issues with non-linearity and waveform limitations [11]. This highlights the need for a fully integrated, accurate, and low-power ECAFE solution.